Reconfigurable Telltale (RTT) Indicators

WARNING: This page is about a different car, the 2017 Lincoln Navigator and 2017 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.

4WD (2WD, 4X4 L, 4X4 H, 4X4 A And 2 H)

The IPC receives the 4WD status from the TCCM. If the vehicle is shifted into 2WD, 4WD auto or 4WD low or high, the TCCM sends the IPC the 2WD, 4x4 auto, 4x4 high or 4x4 low message to illuminate the applicable Reconfigurable Telltale (RTT).

Charging System

The charging system Reconfigurable Telltale (RTT) is controlled by the IPC based upon data received from the BCM. The BCM receives the battery charge low message from the PCM. When a fault is detected in the charging system, the BCM sends the IPC the battery charge low message to illuminate the charging system Reconfigurable Telltale (RTT). Refer to Charging System for additional information on the charging system operation.

Cruise Control

The IPC receives the cruise control status display and cruise control set speed display messages from the PCM.

When the cruise control switch is placed in the ON position, the PCM sends the IPC a standby mode request through the cruise control status display message and the IPC illuminates the cruise control indicator in gray. When the cruise control is engaged, the IPC changes the cruise control indicator illumination from gray to green and the set speed is displayed in the set speed display area.

Door And Liftgate Ajar

The IPC receives the door ajar status for the LF, RF, LR, RR and the liftgate ajar switches from the BCM. When the IPC receives a driver door, passenger door, left rear door, passenger rear door or liftgate ajar status message from the BCM that one or more doors are open or ajar, the IPC illuminates the appropriate door ajar Reconfigurable Telltale (RTT).

Engine Over-Temperature

The PCM uses the CHT sensor to measure the engine temperature. The IPC receives the engine coolant temperature data message from the PCM. The IPC requires 2 basic messaged inputs to control the engine over-temperature Reconfigurable Telltale (RTT). The first is the engine coolant temperature data message. The second is an engine overheat mitigation message. When the PCM sends the engine coolant temperature data or engine overheat mitigation message, the IPC illuminates the engine over-temperature Reconfigurable Telltale (RTT).

Hill Descent Control

The hill descent control system maintains vehicle speed on a downhill grade at operating speeds between 3.2 km/h (2 mph) and 32.2 km/h (20 mph). The system goes into standby mode on a flat or uphill terrain. The system deactivates at speeds above 64.4 km/h (40 mph). During periods of sustained use, the hill descent control system may automatically deactivate in order to cool the braking system.

When the hill descent control is engaged, the PCM then sends a message to the ABS module requesting system activation. The ABS module uses inputs from the RCM and wheel speed sensors to determine the mode of operation.

The IPC receives the hill descent message display message from the ABS module. The message center also displays hill descent control messages to inform the driver they have entered or exited various states of the hill descent control function.

Low Fuel

The IPC uses fuel level, running average fuel economy, odometer counts and fuel flow data to calculate the DTE. The low fuel Reconfigurable Telltale (RTT) is controlled using the calculated DTE. When the DTE display is 120 km (75 miles) (with a MyKey ® programmed key) or 80 km (50 miles) (with an administrator key) to empty or less, the IPC illuminates the low fuel Reconfigurable Telltale (RTT).

Low Oil Pressure

The engine oil pressure switch is hardwired to the PCM. The PCM sends the engine speed and oil pressure warning indicator messages to the IPC. The IPC requires engine Revolutions Per Minute (RPM) above 400 Revolutions Per Minute (RPM) before the message center displays the low oil pressure Reconfigurable Telltale (RTT).

The PCM provides a reference voltage to the engine oil pressure switch when the ignition is in RUN. With the engine running and low or no oil pressure, the engine oil pressure switch remains open. The PCM detects no change in the reference voltage and provides the IPC a request to illuminate the low oil pressure warning indicator. With the engine running and sufficient oil pressure, the engine oil pressure switch closes, pulling the reference voltage low. The PCM detects the low reference voltage and provides the IPC a request to turn off the low oil pressure warning indicator.

The engine oil pressure switch is hardwired to the PCM. The IPC receives the oil pressure warning message and the engine Revolutions Per Minute (RPM) message from the PCM. With the KOEO, the IPC does not display the low oil pressure Reconfigurable Telltale (RTT) until the engine is started and it receives the engine Revolutions Per Minute (RPM) message.

Low Washer Fluid

The low washer fluid level sensor is hardwired to the IPC through a single signal circuit. The low washer fluid sensor is grounded through a separate ground circuit. The IPC provides a battery reference voltage to the washer fluid level switch. When the washer fluid is low, the washer fluid level switch closes to ground, pulling the reference voltage low. When the IPC detects the washer fluid input pulled low, it illuminates the low washer fluid level Reconfigurable Telltale (RTT).

Powertrain Malfunction (Wrench)

The IPC receives the engine service required and the transmission service required messages from the PCM and the 4x4 range fault message from the TCCM.

When a fault condition exists in the ETC system, the PCM provides the IPC with the engine service required message to illuminate the powertrain malfunction (wrench) Reconfigurable Telltale (RTT).

When a fault condition exists in the transmission, the PCM provides the IPC with the transmission service required message to illuminate the powertrain malfunction (wrench) Reconfigurable Telltale (RTT).

When a fault condition exists in the 4WD system, the PCM provides the IPC with the 4x4 range fault message to illuminate the powertrain malfunction (wrench) Reconfigurable Telltale (RTT).

Tow Haul

The tow haul Reconfigurable Telltale (RTT) illuminates when the tow haul system has been engaged and is actively providing tow haul control for the vehicle. When the vehicle is actively providing tow haul control, the PCM sends the transmission tow haul mode message to the IPC to illuminate the tow haul Reconfigurable Telltale (RTT).